Cutting-off tool



R-. A. PEACOCK.

CUTTING OFF TOOL.

APPLICATION FILED MAYIT, I920.

Patented Apr. 12, 1921.

and which embodies means for advancing UNITED- STATES rATENT OFFICE.

ROBERT A. PEACOCK, OF DELAWARE CITY DELAWARE.

CUTTING-OFF TOOL.

To all whom it may concern:

Be it known that I, ROBERT A. PnAoooK, a citizen of the United States, residing at Delaware City, in the county of New Castle and State of Delaware, have invented certain new and useful Improvements in Cutting-Off Tools, of which the following is a specification. e

The present invention relates to engine lathe attachments, and more particularly to a holderfor cutting-off tools. a

An object of the resent invention is to provide a holder 0 this character which may be mounted in the usual tool post or other support provided for maintaining the usualcutting-ofi' tool in position, which may be adjusted in the manner of 'ad'justing such tools; which constitutes a brace for supporting the cutting tool and for reducing vibraq tion thereof incident to the cutting action;

the cutter in the holder so that fine adjustments may be made during the use of the cutter. i Another object of the present invention is to provide a tool holder ofthis character which is of relatively simple construction, which is compact in form; which permitsthe quick'and easy removal andreplacement of the "cutter; and which may be economically manufactured. y i The above, and various other objects and advantages of this invention will in part be described in, and in part be understood from,

the following detailed description of the present preferred embodiment, the same be ing illustrated in the accompanying drawin wherein; e

igure 1 is a side elevation of a tool holder constructed according to the present invention and having a cutter mounted therein.

Fig. 2 is a horizontal section taken through the holder with the cutter therein on a plane substantiallymidway between the upper and lower edges of the holder. a Fig. 3 is a fragmentary enlarged view of the inner end of the cutter, showing the socket'form'ed therein. s

Fig. 4; is a fragmentary sectional view enlarged of the head end of the adjusting screwfor fitting in the socket of the cutter, and

Fig. 5 is an enlarged "transverse section taken through the holder with the cutter mounted therein. 1 e

Specification of Letters Patent. Patented Apr. 12,1921.

Application filed May 17, 1920. Serial No. 382,164.

reference throughout the several views, 10

designates a cutter bar which is of the usual type, and known to the trade as the Armstrong cutter.

This cutter bar lOis provided at its outer end with a d1agonally cut edge 11' which is given a desired configuration and which extends from edge to edge of the cutter form- 1ng a cutting point 12 atone edge which pro ects longitudinally beyond the other edge of the cutter bar. I

As best. shown in Fig. 3 theinner' end of the cutter bar 10 is provided with a socket 13 whichmay be formed by stamping or machining and which opens through therear end of the cutter bar forming thereat in-- wardly facing shoulders 14:. Opposed to the shoul ers 14 are shoiilders 15 formed in the forward end of the socket 13 and the shoulders 14 and 15 are adapted to'take up the endwise thrust imposed upon the cutter blade 10' by the feed screw, which will be later described. Between the shoulders 15 the cutter bar 10 is provided with a depression 16 to accommodate the forward end of the feed screw. I The body of the holder comprises a metal- 110 block 17 of suitable length, thickness," and width, and which has in one lateral face an undercut substantially clove-tailed socket or groove 18 extending throughout the length of the holder 17 and shaped in crosssectionalconfiguration to the transverse contour of the cutter bar 10 for snugly receiving the same, as best illustrated in Fig. 5. It will be noted that the upper edge portion of the cutter bar 10 is of greater thickness than the lower edge portion thereof, and that the slot 18 is correspondingly shaped so as to offset any vibration or loose play of the cutter bar in the holder. This iiicreased thickness at the upper edge of the cutter'bar is for the purpose of strengthening and reinforcing the cutter point 12 relatively long feed screw 21 equipped on-its outer end with a crank handle 22 and adapted at its inner end for interlocking engagement with the cutter bar 10. I

As best shown in Fig. 4:, the feed screw 21 is provided with a reduced shank 23 of a size adapted to fit snugly in the opening 5,

in the rear end of the cutter bar 10, and the shank 23 is adaptedto project into the socket 13 between the shoulders 14:. The outer end portion 2'of the shank is tapered or is given substantial frusto-conical formation'to receivein binding engagement thereover a head piece or block which is pref-.

erably of exterior cylindrical contour and is of a: length and diameter adapted to closely fit the walls and shoulders of the recess 13. This headf piece or block is adapted to interlock the'feed screw 21 to the cutter bar 10 and to form with the cutter bar a swivel joint. The forward end of the head 25 is adapted to bear against the for-I ward shoulders 15, while the rear end of the head 25 is adapted to engage the, shoulders 14:.

The head 25 is riveted upon the conical portion 24 0f the shank by means of the swagedor upset portion 26 of the shank 'whichis turned over against the outer end of the'head. The advantage'of the conical mounting of the head is that forward thrust of the feed s crew, which is the greatest strain or thrust onthe parts, tends to bind the head 25 more firmly upon the stem. The forward end of the holder'17 is provided with a concavity 27 extending from. edge to edge of the holder, and the upper edge :of

the'holder is preferably'notched, as at 28 in registry with the upper edge of thebar lOfor permitting the free passage of chips which are projected from the work by the cutting point 12. e

The operatlonof the device is apparent,

, forwhen the holder 17 is used, it is mounted on the tool post in thevordinary manner and may-be set up in close proximity to the worln The feed screw 21 may be turned to advance the cutter bar 10 against the work and as the holder 17 approaches in close proximity to the work it supports the cutter bar 10 and holds'the latter from vibrating. In this manner the undue yielding of the cutter-bar is prevented with the result that there is less likelihood of injuring the cut ting tool, the work is more uniform, and a finer adjustment may be made inthe use of the tool.

- The cutter bar 10 may be quickly removed and replaced by removal of the head 19 which, whendisengaged from the body'17 permits the longitudinal withdrawal of the cutter 10 through the rear end of the body 17. .As soon as the screw feed, and cutter have'been sufficiently withdrawn to free the head 19 from the body 17 the head 25 of the screw feed maybe lifted laterally out of the socket 13 to separate the parts. 7 Y

It is, of, course, understood that various changes and modifications may be made in bar, a head'mounted on the inner end'of said body portion, a feed screw threadedthrough the head and projecting into said slot, and a swivel connection between the feedscrew and said cutter bar and arranged detachably in'said socket for lmoving the cutter bar in said body portion; In a tool holder, the combination of a flat cutter bar, a body portion having an undercut slot one side adapted to receive the cutter bar therein, a head on the inner end of the body portion, a feed screw 7 threadedthrough said head 'coaxially with i the undercut slot, and aconnection between the cutter bar and the feed screw whereby operation of the feed screw is adapted to shift said cutter bar longitudinally in the slot for projecting the cutter bar from the forward end oftheloodyportion,

3 In a tool'hold'enthe combinationof a 7 flat cutter 'barlhaving a forward cutting edge and provided with a socket in its inner end opening through the rear extremity of thecutter bar, a-body portion having anundercutslot formed intone side adaptedtoreceive the cutter bar therein, a head' de'tachably mounted onthe rear, end of the body portion, a feed screw threaded through the head coaxially' with the undercut slot, and

a block mounted upon the forward end of the feed screw adapted to fit in the socket of the cutter bar whereby operation of the feed screwis' adapted to move said block againstthe walls of the socket for advancing and retracting the cutter bar during adjustment thereof in the body portion. 7

i 1. In a tool holder, the combination ofa body portion adaptedto be mounted on a 'latheand having an outer concave-f end adapted to be arranged in proximity to the work and equipped in one side with. an undercut slot extending from end to end of the body portion andopening throughfsaid ends, a cutter bar slidably mounted inithe slot having a cutting edge adapted to pro 7 ject through the forward end of the cutter bar for contact with the work, a cap piece on therear end of the body portion, a feed screw carried by the cap piece coaxially with said slot, and a swivel connection between the feed screw and the rear end of the cutter bar, whereby operation of the feed screw is adapted to advance said cutter bar from the forward end of the body portion into contact with the work.

5. In a tool holder, the combination of a body portion provided with an undercut slot in one side extending throughout the length of the body portion, a cutter bar fitted in the slot to move longitudinally in the body portion, a feed screw mounted in the inner end of the body portion and provided at its forward end with a tapering shank, a a

cylindrical head having a coaxially taper-in bore adapted to fit said shank, said shan being riveted at its outer end to maintain the head on the shank, said cutter bar having a socket formed therein near its inner end and provided with an opening extending from the socket through said inner" end, said head being adapted to fit in said socket and said shank being adapted to project through the opening leading from the socket whereby said head is engaged at opposite ends with the front and rear walls of the socket, and means for turning said feed screw.

ROBERT A. PEACOGK. 

